Heat regenerator containing metal packing material coated with a lubricant



Patented Mar. 9, 1954 HEAT REGENER ATOR CONTAINING METAL PACKINGMATERIAL COATED WITH A LU- BRIOANT George H. Zenner and Russell W.Houvener, Kenmore, N. Y., 'assignors, by mesne assignments, to UnionCarbide and Carbon Corporation, a

corporation of New York No Drawing. Application November 30, 1949,Serial No. 130,341

8 Claims.

This invention relates to an improved heat regenerator packing materialwhich has been lubricated to reduce dusting.

1 It has been proposed that stone or metal pel- 2 at room temperature,as for example, tricres yl phosphate and the liquid polymers of dimethylsilicone and chlorotrifluoroethylene. The lubricant coating may beapplied in any known manlets, within the critical size range of 1 5'inch to '5 ner, for example by rolling the pellets in a drum inch indiameter, may be substituted for the containing the lubricant. Theefliciency of heat Frankl "aluminum pancakes, presently used asregenerator packing material is measured in a low-temperature heatregenerator packing, terms of the fluid pressure drop through thewithout lowering the heat exchange efficiency of regenerator and themean temperature diiferthe regenerator. Because inexpensive sources oflo enceof the fluid flowing therethrough. Lubrisupply for such pelletsare available, e. g. alumieating the pellet packing material causes onlyan mnn'or iron shot or stone beach pebbles, a great immaterial increasein the pressure drop and saving in regenerator construction and main hasno effect upon the mean temperature difi'ertenance cost may beefi'ected. ence. At th same time, it greatly reduces dust- The Friinkllow temperature regenerator or ing and increases the life' of thepacking material. "cold accumulator and a low temperature gas The tabledemonstrates the reduction in dustseparation system in which it is used,is deing resulting from a lubricant coating as shown scribed in Unitedstates Patent 1,890,646 of by an 85 hour milling test. It should benoted Mathias Frankl and the improved regenerator that a part of thedust in the tests on coated packing according to this invention isespecially as samples "was graphite or molybdenum disulphide useful forsuch systems in which a pair of the rather than pellet material.regenerators efiects heat exchange between a TABLE compressed gasmixture to be cooled and a cold l separation product flowed alternatelythrough 317%:t J lubncation dusting each regenerator of the pair.

Such pellet regenerator packing while inex- Percent pensive andefficient is subject to a certain Pellet Material Lubricant 25%? ig f52$; amount of "dusting" or powdering in operation. cant mm) Thisresults from the rapid and reversing fluid flow through the regenerator.Dusting is dfie- M inclgtolfiinch Graphite 0.05 was 0.009; creasedsomewhat by holding the pellets tigh 1y in 1 122:] with mechanicalpressure on the packing $0 1 ch o i umi "f 182 M22 mate It increaseswith increased and velocl lty of the fluid flow and hence is moretrouble- Do glll n iii lfaif M82 M16 some in low-temperature gasseparation plants g gg ng M7 with substantial pressure difierencebetween the infiowing gas mixture and outflowl'ng separation aluminumpane used mm m'pmhonom This accounts product. Dusting is disadvantageousnot .only tor the excess of lubricant over that consumed in coating thestone because impurities are introduced into the prodnot but alsobecause in time the pellet size falls 40 while this invention In beenexplained with below the diameter range- The particular reference toheat regenerators for low- 8510mm? then amps and a replacementtemperature gas separation plants, it is not in- Of the Packing materialmay be necessarytended to be so limited and is equally applicable Theobject of this invention is to provide a t pellet packing material used1 mgher pellet een rator p c material of greatly perature heatregenerators and on pellet packing reduced inability and no materialreduction of of es other t those previously noted as packing efliciency.m t emcient The invention is based on the discovery that w l im; dustingm y b Substantially reduced y coatin 1. A heat regenerator containingpacking methe pellets with a lubricant. In heat regen- 5 term comprisinginch to inch diameter craters u in lowmperature air separati n pelletsconstituted of metal selected from the plants the lubricant must also benon-oxidizable. group consisting of aluminum shot and iron Graphite andmolybdenum disulphide are parshot, such pellets having a. tendency toabrade ticularly advantgeous solid lubricants for this and dust whensubject to repeated rapid changes purpose, as are certain lubricants'whlch'are liquid of fluid flow through the regenerator, said pel- 3lets being each coated with a lubricant selected from the groupconsisting oi graphite and molybdenum disulphide.

2. A heat regenerator containing packing material comprising aluminumpellets of 1% inch to inch diameter, said pellets being of a heatstoring material having a tendency to abrade and dust when subject torepeated rapid changes of fluid flow through the regenerator, saidpellets being each coated with graphite.

3. A heat regenerator containing packing material comprising 1 inch toinch diameter pellets constituted of iron shot, such pellets having atendency to abrade and dust when subject to repeated rapid changes offluid flow through the regenerator, said pellets being each coated withgraphite.

4. A heat regenerator containing packing material comprising 1% inch toinch diameter pellets constituted of iron shot, such pellets having atendency to abrade and dust when sublest to repeated rapid changes offluid flow through the regenerator, said pellets being each coated withmolybdenum disulphide.

5. A heat regenerator containing packing material comprising aluminumpellets of inch to inch diameter, said pellets being of a heat storingmaterial having a tendency to abrade and dust when subject to repeatedrapid changes of fluid flow through the regenerator, said pellets beingeach coated with molybdenum disulphide.

6. A low-temperature heat regenerator for eftesting heat exchangebetween a compressed gas mixture to be cooled and a cold separationproduct flowed alternately therethrough, said regenerator containingpacking material comprising metal pellets of inch to inch diameter, saidpellets being of a heat storing material having a tendency to abrade anddust when subject to repeated rapid changes of fluid flow through the 4regenerator, said pellets being each coated with a lubricant selectedfrom the group consisting of graphite and molybdenum disulphide.

7. A low-temperature heat regenerator for ef fecting heat exchangebetween a compressed gas mixture to be cooled and a cold separationproduct flowed alternately therethrough, said regenerator containingpacking material comprising metal pellets of inch to inch diameter, saidpellets being of a heat storing material having a tendency to abrade anddust when subject to repeated rapid changes of fluid flow through theregenerator, said pellets being each coated with molybdenum disulphide.

8. A low-temperature heat regenerator for effecting heat exchangebetween a compressed gas mixture to be cooled and a cold separationproduct flowed alternately therethrough, said regenerator containingpacking material comprising metal pellets of 1; inch to inch diameter,said pellets being of a heat storing material having a tendency toabrade and dust when subject to repeated rapid changes of fluid flowthrough the regenerator, said pellets being each coated with molybdenumdisulphide.

GEORGE H. ZENNER. RUSSELL W. HOUVENER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,987,092 Winkler Jan. 8, 1935 2,102,214 Parker Dec. 14, 19372,157,155 Work May 9, 1939 2,280,886 Brace Apr. 28, 1942 2,387,872 BellOct. 30. 1945 2,461,011 Taylor et al Feb. 9, 1949 2,531,725 Church Nov.28, 1950 2,600,078 Schutte et a1 June 10, 1952

6. A LOW-TEMPERATURE HEAT REGENERATOR FOR EFFECTING HEAT EXCHANGEBETWEEN A COMPRESSED GAS MIXTURE TO BE COOLED AND A COLD SEPARATIONPRODUCT FLOWED ALTERNATELY THERETHROUGH, SAID REGENERATOR CONTAININGPACKING MATERIAL COMPRISING METAL PELLETS OF 3/16 INCH TO 5/8 INCHDIAMETER, SAID PELLETS BEING OF A HEAT STORING MATERIAL HAVING ATENDENCY TO ABRADE AND DUST WHEN SUBJECTED TO REPEATED RAPID CHANGES OFFLUID FLOW THROUGH THE REGENERATOR. SAID PELLETS BEING EACH COATED WITHA LUBRICANT SELECTED FROM THE GROUP CONSISTING OF GRAPHITE ANDMOLYBDENUM DISULPHIDE.